Navigation

Has Dr Venter created artificial life? May 26, 2010

In the light of Craig Venter’s new claims to have created artificial life we are publishing as an article here part of the chapter in “Who made God?” that deals with Venter’s work.

Life in a cake mixer

We shall spend this chapter in pursuit of the jellypod. That’s my pet name for Haldane’s ‘minimal organism’ — the simplest entity that could be called ‘living’ and which we discussed briefly at the start of chapter 12. No disrespect is intended; jellypod is just more memorable than ‘minimal organism’.

In chapter 12, having pointed out the enormous complexity of even the simplest life-form known to us today, we put the jellypod on one side to seek out the essence of physical life. This turned out to be organised information — something, moreover, that cannot be stored, transmitted or put to work without the use of communication or ‘language’. This is just what we would expect on the biblical hypothesis of God, since the Bible attributes both the origin and maintenance of the natural world to God’s ‘spoken word’ — a metaphor that embraces the twin ideas of command and communication. It is no surprise, therefore, that the molecular foundations of life are stacked full of information and bear all the marks of advanced language.

But now we must let the jellypods have their day and the atheists their say — for they claim (the atheists, that is, not the jellypods) that not only was the origin of molecular information and language a purely material accident but so was the whole jellypod caboodle. Science writer Paul Davies declares: ‘Science takes as its starting point the assumption that life wasn’t made by a god or supernatural being: it happened unaided and spontaneously, as a natural process’[i]. Let’s see if this highly questionable claim stands up.

Baking bacteria

We have already seen that our jellypod must have resembled a tiny though highly sophisticated factory, but we must now look deeper into its inner workings to see how they might have arisen by chance (or not, as the case may be). How could we prove that, in one giant leap for jellypods, the first ‘minimal organism’ just happened? Actually, we never could, but we might be able to render the idea plausible. One way would be to manufacture such an entity in the laboratory using only undirected chemistry and materials that could have been present on an ancient lifeless earth. In fact, Haldane envisaged just such a project when he said, ‘… our descendants may be able to make one’ (Ch. 12 headline quote). But let’s not forget how he went on: ‘but we must give up the idea that such an organism could have been produced in the past, except by a similar pre-existing organism or by an agent, natural or supernatural, at least as intelligent as ourselves, and with a good deal more knowledge’. However, when it comes to jellypods, materialists do not lack for optimism, and the ‘idea’ that Haldane says we should ‘give up’ has, in fact, been pursued to this day with great vigour and expense. Here’s an example.

In January 2008, the London Times published an article headlined, ‘The life-giving miracle of Dr Venter’[ii]. It celebrated the achievement of US scientist Craig Venter and co-workers in synthesising in the laboratory a bacterial DNA sequence containing over 580,000 base pairs. Among other things, the article claimed that chemistry has abolished the idea that life is something special. It declared: ‘Dr Venter … is simply the latest in a long line of biochemists who have punctured life’s claims to specialness. Until 1828 it was believed that life, with its so-called “vital forces”, owed nothing to science …’. The idea being promoted in the article is, of course, that life is just complicated chemistry, nothing more. That is why (they say) life was able to evolve by the chance combination of ordinary non-living chemicals. But there are several basic fallacies in this ‘reductionist’ approach to life’s origin.

Firstly, Dr Venter’s chemical tour de force demonstrates that to produce a meaningful string of DNA requires a lot of hard work by highly skilled and intelligent chemists. No one suggests that he and his team simply poured the necessary chemical ingredients into a cake mixer, set it on automatic and took a vacation. And that is just to copy an existing DNA molecule. To create the first such molecule from scratch would, I suggest, have required an infinitely greater input of intelligence. It simply isn’t good enough to claim that the cake mixer actually will produce a ‘life-giving miracle’ as long as you run it for a thousand million years or so before you bake the cake. Yet that, in effect, is what the atheist is compelled to claim — as Richard Dawkins seems to confirm in the following passage:

‘Suppose we want to suggest, for instance, that life began when both DNA and its protein-based replication machinery spontaneously chanced to come into existence. We can allow ourselves the luxury of such an extravagant theory, provided that the odds against this coincidence occurring on a planet do not exceed 100 billion billion to one’ (emphasis added)[iii]. We can now see more clearly why Dawkins needs hand-waving statues and ballistic cows. He first maintains that there is some non-zero mathematical probability that all the chemical ‘components’ required to build a jellypod will join together — in the correct sequence, at the same time and in the same place. He then assumes that this must happen given sufficient time. Finally, he cleverly reduces the time required by allowing the process to proceed simultaneously on a billion planets, any one of which could get lucky. However, he is still lost in the never-never land of mathematical probabilities and ignores completely the world of chemical reality.

Jellypod blues

Our quotes from Haldane in the previous chapter, and from double-helix discoverer Francis Crick in this, confirm that any prospect of building a jellypod from scratch by accidental chemical reactions must be viewed with the deepest scepticism. I’ll call this gloomy prognosis the jellypod blues.

In September 1972 I was privileged to be one of four specially invited speakers at the dedication symposium of the Michigan Molecular Institute — the others being Nobel Prize winners Paul Flory and Melvin Calvin (both chemists) and medical scientist Dr Donald J. Lyman[iv]. Melvin Calvin’s lecture addressed the puzzling ‘origin of life’ problem concerning how amino acids might have linked together to form protein-like molecules in an aqueous pre-biological world. Basically, they can’t, because water always disrupts such linkages. The only way the problem can be overcome is by providing highly specialised catalyst molecules that help the amino acids link together in spite of the effects of water (this, of course, is what happens in the living cell, but we’re talking here about a time before living cells existed). Calvin showed how such pre-biological catalysts might have worked — but was well aware that they could only assist if they happened to be there in the right place at the right time (a highly improbable scenario).

The jellypod blues begin, therefore, when we realise that to create a jellypod spontaneously would require real chemistry to take place in some primeval chemical soup or similar environment. Not only would amino-acids have to link together to form protein chains but at the same time and place, nucleotides (the building blocks of DNA) would also have to link together into polymer chains, again in the presence of water. But water works against chain formation in both proteins and nucleic acids, so that such molecules could only be built from scratch if a variety of highly specific catalysts just happened to be conveniently on hand. In short, the chance creation of proteins and DNA invokes extremely implausible chemistry. Recognising this problem, some have suggested that the first biopolymers were formed in dry conditions on mineral surfaces, but the idea has never really caught on. Whenever biologists look for signs of extra-terrestrial life, the first thing they want to see is water, since life as we know it cannot exist without it.

But could mineral surfaces provide the catalytic ‘muscle’ to overcome the effects of water and allow biopolymers to be built up? It is known that certain crystalline minerals such as zeolites do display catalytic activity and can facilitate polymer formation (chain-building), but they only work under carefully controlled conditions. Some technical publications have explored this route to the formation of polymers of amino-acids and bases. For example, computer modelling has been used to predict how amino-acids might behave within the microscopic pores of zeolites[v], while studies of the adsorption of bases on graphite have shown that some are adsorbed more strongly than others[vi]. But the relevance of such results to the origin of life is both remote and speculative, and to date nothing resembling a protein or nucleic acid polymer has ever been produced by such methods.

As a consultant to the Dow Chemical Company for more than thirty years, I frequently worked with chemists whose job it was to synthesise novel long-chain polymers. Anyone involved in such endeavours knows that success depends on using highly purified starting materials and specialised catalysts. It is impossible to build small molecules into long-chain polymers if there are impurities in the system, because the impurities ‘poison’ the chemical reaction and contaminate the catalysts. It is ludicrous to suggest that amino-acids or nucleotides (even if present in sufficient concentrations) could spontaneously link together in long chains in a chemical environment containing a random assortment of chemicals.

Glove soup

The jellypod blues deepen when you realise that any particular amino-acid or nucleotide would be present in a ‘primeval soup’ in several different forms called ‘isomers’. [the chapter continues but you will have to read the book to find out how!]